Certain aircraft precision approach guidance systems, for example, require accurate positioning relative to the runway with a high level of integrity. Precision approach guidance systems in use today typically require ground-based electronic navigation components with at least one installation at each airport, and in many cases multiple installations to service approaches to all qualifying runways. A guidance system that provides precision guidance to an aircraft without the use of ground-based electronic navigation components is needed. Similar needs exist for spacecraft and other types of flying craft.